Marley graphed the function y = 6(13)xy = 6(13)x in her graphing calculator, as shown below.



An asymptote is a line or curve that the graph of a relation approaches more and more closely the further the graph is followed. Which of the following represents an asymptote of the graph?

A.

x = 0

B.

y = 0

C.

x = 1/3

D.

y = 6

1 answer

To determine the asymptote of the function \( y = 6(13)^x \), let's analyze its behavior as \( x \) approaches certain values and its general structure.

  1. The function \( y = 6(13)^x \) is an exponential function. Exponential functions of this form do not have vertical asymptotes, but they may have horizontal asymptotes.

  2. As \( x \) approaches negative infinity (\( x \to -\infty \)), \( (13)^x \) approaches zero. Therefore, \( y \) approaches zero: \[ \lim_{x \to -\infty} y = \lim_{x \to -\infty} 6(13)^x = 6 \cdot 0 = 0 \] This indicates that there is a horizontal asymptote at \( y = 0 \).

  3. As \( x \) increases (as \( x \to \infty \)), \( (13)^x \) increases without bound, and therefore \( y \) also increases without bound.

Given this analysis, the only correct option for an asymptote is:

B. \( y = 0 \)

This represents the horizontal asymptote where the graph approaches as \( x \) decreases.